Reactions of Organotin (IV) Compounds with Platinum Complexes Part (I) : Oxidative-Addition Reaction of SnRxCl4-x with [Pt(PR3')n], R' = Et, n = 3 or 4 and R' = Cyc, n = 2

Abstract

The complex [Pt(PEt₃)_n] (n = 3 or 4) reacts oxidatively with SnR₂Cl₂

(R = Me, Et) to give trans-[PtCl(SnR₂Cl)(PEt₃)₂] which may also be

obtained by treatment of [Pt(C₂H₄)(PPh₃)₂] and SnR₂Cl₂ followed by

addition of two molar equivalents of PEt₃. The corresponding reaction of

SnPh₂Cl₂ likewise gives the product of insertion of Pt(0) into Sn-Cl

bonds when the reaction was carried out at –3DºC, but at room

temperature the product of insertion into the Sn-Ph bond is obtained. Tin

compounds SnR₃Cl (R = Me, Ph) give product of insertion into Sn-R

bonds at room temperature, but only SnMe₃Cl gives product of insertion

into Sn-Cl bonds at –3DºC. The compounds SnPh₄ and SnPh₃Me undergo

insertion into Sn-Ph bonds to form both the cis- and trans- isomers. The

dinuclear tin compound Sn₂Ph₆ reacts with [Pt(PEt₃)₄] to give the complexes

trans-[Pt(SnPh₃)₂(PEt₃)₂] and cis- and trans-[PtPh(SnPh₃)(PEt₃)₂],

while its reaction with [Pt(C₂H₄)(PPh₃)₂] followed by addition of an

equimolar quantity of PEt₃ gives cis- and trans-[PtPh(Sn₂Ph₅)(PEt₃)₂]

along with the breakdown products cis- and trans-[PtPh(SnPh₃)(PEt₃)₂].

Similar observations were made for the reaction of [Pt(PCyc₃)₂] with

SnR₂Cl₂ (R = Me, Et, Bu, Ph) to give trans-[PtCl(SnR₂Cl)(PCyc₃)₂], with

SnR₃Cl (R = Me, Bu, Cl) to give trans-[PtCl(SnR₃)(PCyc₃)₂], and with

SnPh₃Cl to give cis- and trans-[PtPh(SnPh₂Cl)(PCyc₃)₂]. The reactions of

the lead compounds PbR₃Cl (R = Me, Ph) with [Pt(PCyc₃)₂] were found

to proceed analogously. The compound PbMe₃Cl gives the product of

insertion into Pb-Cl bonds whereas PbPh₃Cl gives product of insertion

into Pb-Ph bonds as SnR₃Cl compounds do. The complexes and their

decomposition products were identified by ³¹P NMR spectroscopy.